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Biomedical subjects

I Kawamura

Publications and source records attributed to I Kawamura.

129 records · Page 8Linked to original sources

Possible involvement of calpain in the growth of estrogen receptor positive breast cancer cells.

Calpain (Ca2(+)-activated neutral protease, EC 3.4.22.17) has been reported to hydrolyze the estrogen receptor (ER). However, there has been no report available regarding the role of calpain in the growth of breast cancer cells. To investigate the role of calpain in the growth of various breast cancer cell lines, we employed a synthetic peptide, calpeptin, which is a cell permeable specific inhibitor of calpain. Calpeptin inhibited the cell growth of ER positive breast cancer cells, such as MCF-7, T-47D, and ZR-75-1 in a dose dependent manner in the presence of E2. However, the growth of ER negative breast cancer cells, MDA-MB-231, was not inhibited by calpeptin. It is suggested that calpain plays an important role in the growth of ER positive breast cancer cells.

Animals↗

Mechanism of growth inhibition by calpain inhibitor in MCF-7 cells.

BACKGROUND: A calpain inhibitor, calpeptin, inhibited the cell growth of ER (estrogen receptor) positive breast cancer cells, such as MCF-7, T-47D, and ZR-75-1 in the presence of E2. The mechanism of this inhibition has not been clarified yet. MATERIALS AND METHODS: MCF-7 cells were employed to investigate the mechanism of the inhibition. We studied the effect of calpeptin on the secretion of insulin-like growth factor-I (IGF-I) and transforming growth factor (TGF-alpha). RESULTS: The secretion of IGF-I or TGF-alpha was not changed by calpeptin either in the presence or absence of E2. Moreover, the binding of IGF-I or TGF-alpha to MCF-7 cells augmented by the addition of E2 was not affected by calpeptin. CONCLUSIONS: These results indicated that the inhibition of cell growth in MCF-7 by calpeptin was not due to the modulation of autocrine growth factors and their receptors.

Breast Neoplasms↗

Effect of FR143430, a novel cytokine suppressive agent, on adenocarcinoma colon26-induced cachexia in mice.

Cancer cachexia, characterized by weight loss and progressive tissue wasting, has been postulated to be mediated by cytokines. In this study the effect of FR143430, (2-(4-fluorophenyl)-4, 5, 6, 7-tetrahydro-3-(4-pyridyl)pyrazolo[1, 5-a]pyrimidine monohydrochloride), an inhibitor of Interleukin-1 and Tumor necrosis factor-a (TNF- a), on adenocarcinoma colon26-induced cachexia was investigated in mice. Tumor growth was not affected. Nevertheless, treatment with FR143430 (0.1 to lmg) into the tumor resulted in the attenuation of the reduction in body weight, food intake, epididymal fat and carcass weight, the decrease in the circulating levels of triglyceride and glucose, and the increase in the circulating levels of total cholesterol, non esterified free fatty acid (NEFA) and total protein, which were induced by the presence of the tumor. However, oral treatment with FR143430 failed to show an inhibitory effect on cachexia induction. Overall, this study demonstrated that the cachexia induced by colon26 was alleviated by the injection of FR143430 into the tumor in sufficient quantity, without any effect on tumor growth, suggesting the potential utility of cytokine suppressive agents e for the treatment of cancer cachexia.

Animals↗